BLOOD FLOW IN THE EXTREMITIES OF PATIENTS WITH HEART DISEASE

Physicians have long known of the pallor of aortic insufficiency and of the "languor of the arterial circulation causing the extremities and surface to be chilly"¹ in heart failure. The recent interest in peripheral blood flow led to the discovery that in aortic regurgitation the skin may be flushed and warm² and that rapid blood flow in the limbs may be present in spite of circulatory embarrassment. Many observers have estimated the flow through the limbs by inference from the gas content of the venous blood, not by the more direct plethysmographic method. It probably is permissible to assume that the metabolism of resting limbs is fairly constant and that the amount of oxygen removed from each unit of blood passing through the capillaries varies inversely as the total volume of flow. Large differences in oxygen content of arterial and venous blood therefore indicate that only a small